[1511] injectable function not defined on server side

iam using vue-inject to inject custom service.

injector.js

import Vue from 'vue';
import injector from 'vue-inject';

require('../service/postService');
Vue.use(injector);

postService.js

import injector from 'vue-inject';
import axios from 'axios';
injector.service('postService', function () {
  this.getPosts = function () {
    return axios.get(process.env.postsApi);
  }
});

config/nuxt.js

plugins: [
    {src: '~/plugins/jquery.min', ssr: false},
    {src: '~/plugins/injector.js', ssr: true},
  ],

why my injection does'nt work in server side rendering but work in mounted and method events.. :(